JP2000004508A - Battery casing for electric vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To cool a battery without taking external air into battery storing parts inside a casing, to facilitate the guarantee of watertightness, and to make it easily applicable to other car models, using different number of batteries. SOLUTION: Three pieces of battery cells of a cylindrical shape to be connected in series are stored in a casing 25 which is structured with an extruded material of aluminum, in such a way as to contact the inside circumferential surfaces of battery storing spaces 27 passing through the casing in the front-to- rear direction of a car body. The casing 25 comprises two casing units 29, each of which is provided with four battery-storing spaces 27, are coupled to each other at two coupling parts 31 in such a way as to be stacked in two steps, upper and lower. The opening parts at the front and rear ends of the battery-storing spaces 27 are closed in a sealed state via a sealing material with terminal covers, provided with bus bars made conductive to the terminals of the battery cells.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery case for an electric vehicle accommodating a battery used as a power source.

[0002]

2. Description of the Related Art An electric vehicle powered by a battery is
For example, as described in Japanese Patent Application Laid-Open No. 7-81432, a battery is mounted by mounting a battery frame on which a plurality of batteries are mounted on the lower surface of the floor of a vehicle body.

FIG. 7 is an exploded perspective view showing a battery fixing structure using the above-described battery frame as a battery case. The battery frame 1 can mount a plurality of batteries 3, and a cover 5 is provided at an upper opening thereof.
Is secured to the floor member on the underside of the vehicle body using bolts and nuts. At this time, a sealing material is interposed between the battery frame 1 and the vehicle body in order to prevent water from entering the battery frame 1.

[0004] In addition, intake ducts 7 and 9 are mounted on an end surface of the battery frame 1 on the front side of the vehicle body as indicated by an arrow F.
An exhaust duct 1 is provided on the end face on the rear side of the vehicle body indicated by the arrow R.
1, 13, 15, 17 and an exhaust fan 19 are mounted respectively. The air sucked from the intake ducts 7 and 9 by driving the exhaust fan 19 is introduced into the battery frame 1 to cool the battery 3, and
It is discharged from 1, 13, 15, 17 to the outside.

[0005]

However, in such a battery case used for the conventional battery fixing structure of an electric vehicle, the battery 3 is cooled by introducing outside air into the battery frame 1. Therefore, strict quality control is required so that water does not enter the battery frame 1, and the cost man-hours increase. As a waterproof measure, the battery frame 1
Of the sealing material between the vehicle and the underside of the vehicle body, the intake duct 7,
9 and each connection part of the exhaust ducts 11, 13, 15, 17 and the like, there are many water tightness management parts, and it is necessary to inspect the waterproof structure on a vehicle-by-vehicle basis. To check for water leakage, remove the battery frame from the vehicle body. It is extremely difficult to guarantee watertightness. Further, the above-described battery frame 1 does not particularly consider correspondence between vehicle types in which the number of used batteries 3 is different. For example, when the battery frame 1 is used in a vehicle type in which the number of used batteries 3 is smaller than that shown in FIG. In this case, a wasted space in which the battery 3 is not accommodated occurs in the battery frame 1, which is inefficient.

Accordingly, the present invention makes it possible to cool a battery without introducing outside air into a portion in which the battery is housed, to easily assure water tightness, and to easily cope with vehicles having different numbers of used batteries. It is intended to be.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, there is provided a battery housing space for housing a battery cell having terminals at both ends with its outer surface being in close contact with the inner surface. With a plurality, at least one end, an opening in which a terminal cover having a terminal portion capable of conducting to the terminal of the battery cell is hermetically mounted,
The plurality of battery accommodating spaces have a multi-stage stacked shape that is superimposed on each other, and each stage forms an independent case unit, and the case units can be connected to each other.

[0008] According to the battery case of the electric vehicle having such a configuration, the battery cell is housed in the case, so that the outer surface of the battery cell is in close contact with the inner surface of the battery housing space, and furthermore, the case end is closed. By mounting the terminal cover in the opening, the battery housing space is sealed. In addition, the number of battery cells mounted on the vehicle can be changed by using the case alone or in a state of being connected to each other.

According to a second aspect of the present invention, in the configuration of the first aspect, a cooling air introduction space is formed between the single cases.

[0010] According to the above configuration, the outside air is introduced into the cooling air introduction space, so that the battery cells are cooled through the case. Since the battery housing space in the case is sealed by the terminal cover, outside air serving as cooling air does not enter the case.

According to a third aspect of the present invention, in the configuration of the first or second aspect of the present invention, the connecting portion for connecting the single case units is provided with a pair of side walls facing each other at a predetermined interval in one of the single case units. A locking projection protruding in a direction facing each other is provided on the distal end side of the side wall, and the other case unit is located on the base end side of the side wall with respect to the locking projection. Protrusions are provided with locking projections on both sides to prevent them from coming off.

According to the above construction, the locking projection of the projecting piece provided on one of the cases alone is inserted between the side walls on the base side of the side wall than the locking projection of the side walls provided on the other case alone. , The cases are connected to each other.

According to a fourth aspect of the present invention, in the configuration of the third aspect of the present invention, the case unit includes a side wall connected to a protruding piece of the mating case unit and a side wall of the mating case unit. Are provided respectively, and the two cases alone have the same shape.

[0014] According to the above configuration, it is not necessary to make the case units to be connected different from each other, thereby suppressing the manufacturing cost.

[0015]

According to the first aspect of the present invention, since the battery cell is housed in the case, the outer surface of the battery cell is in close contact with the inner surface of the battery housing space, and the terminal cover is provided at the opening at the end of the case. By mounting the case, the battery housing space is sealed, so by installing the case in the flow of outside air, the generated heat is radiated to the outside air via the case and cooled down. Since outside air is prevented from entering the battery housing space, water can be prevented from entering the battery housing space. In addition, the sealing part for waterproofing is only between the end of the case and the terminal cover, and the inspection of the waterproof structure can be performed for each case in which the battery cells are stored, and need not be performed for each vehicle. Watertightness can be easily guaranteed. Furthermore, by using the case alone or in a state of being connected to each other, it is possible to change the number of battery cells mounted on the vehicle, and it is possible to cope with vehicles that require different battery capacities. It will be easy.

According to the second aspect of the present invention, the outside air serving as the cooling air is introduced into the cooling air introduction space to cool the battery cells through the case and does not enter the battery housing space. Water can be prevented from entering.

According to the third aspect of the present invention, the locking projection of the projecting piece provided on the one case alone is inserted between the side walls on the base side of the side wall from the locking projection of the side wall provided on the other case alone. By doing so, it is possible to reliably connect the cases alone.

According to the fourth aspect of the invention, the case unit is provided with a side wall connected to the projecting piece of the case unit on the mating side and a projecting piece connected to the side wall of the case unit on the mating side, respectively. Since the two case units have the same shape, it is not necessary to make the case units to be connected different from each other, and the manufacturing cost can be reduced.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an exploded perspective view of a battery fixing structure of an electric vehicle showing an embodiment of the present invention.
FIG. 2 is a side view of an electric vehicle including the above-described battery fixing structure. The battery cells 23 constituting the battery are:
A plurality of columns each having a terminal 23a at both ends are used. Case 25 accommodating this battery cell 23
As shown in FIG. 3, which is an enlarged front view from the front side of the vehicle body or the rear side of the vehicle body, the vehicle body comprises two extruded members made of aluminum and arranged in parallel in the vehicle width direction. A total of eight battery housing spaces 27 penetrating in the front-rear direction are formed, four in each of the upper and lower stages.

In each of these battery housing spaces 27, three battery cells 23 around which an insulating material 23b is wound are housed in a state of being connected in series. For this reason, in one case 25 having eight battery accommodation spaces 27,
24 battery cells 23 will be accommodated. In this case, since two cases 25 are used, 48 battery cells 23 are used in the entire vehicle.

The inner diameter of each of the battery housing spaces 27 is substantially the same as the outer diameter (including the insulating material 23b) of the battery cell 23. Therefore, in the housing state, the cross section corresponding to the line AA in FIG. As shown in FIG. 4, the outer peripheral surface of the insulating material 23 b provided on the outer periphery of the battery cell 23 comes into close contact with the inner peripheral surface of the battery housing space 27.

As shown in FIG. 3, the case 25 has four battery accommodation spaces 27 on the upper and lower stages, respectively.
Are provided, and each case unit 29 is fixedly connected to each other at two connecting portions 31. The connecting portion 31 is formed of four
The two battery housing spaces 27 are provided at positions in the center of the two battery housing spaces 27, facing the case unit 29 on the other side. The two case units 29 described above have the same shape as each other except that they are arranged upside down and used.

FIG. 5 shows the connecting portion 3 located on the right side in FIG.
FIG. 1 is an enlarged view of FIG. 1, in which a pair of side walls 33 projecting toward the upper case unit 29 is provided on the lower case unit 29;
In FIG. 5, it is formed to extend over the entire length of the case unit 29 in a direction perpendicular to the paper surface. A locking projection 35 is formed at a position of the distal end of each side wall 33 opposite to each other. The locking projection 35 has an insertion inclined surface 35a on the distal side and a locking surface 35b on the proximal side, and is substantially triangular. It has a shape.

On the other hand, on the upper case unit 29, a projecting piece 37 that is engaged with the engaging projection 35 is formed so as to project toward the lower case unit 29. This protruding piece 27
5 also extends in the direction perpendicular to the paper surface of FIG. 5 over the entire length of the case unit 29, and locking projections 39 are formed on both left and right sides thereof. The locking projection 39 is disposed to face the inclined surface 39a that is in sliding contact with the insertion inclined surface 35a of the locking projection 35 when the protruding piece 37 is inserted between the side walls 33, and is opposed to the locking surface 35b after insertion. It has a substantially triangular shape with a locking surface 39b for preventing the protruding piece 37 from coming off.

The connecting portion 31 located on the left side in FIG. 3 has the same shape as that shown in FIG. 5, except that the side wall 33 is provided on the upper case unit 29 and the protruding piece 37 is provided on the lower case unit 29, respectively. Is provided. The side wall 33 and the projecting piece 37
Need not be provided over the entire length of the case unit 29,
It is good also as composition provided with two or more in a predetermined part.

An outer wall 41 protruding downward is provided on both left and right sides of the upper case unit 29 in FIG. 3 over the entire length of the case unit 29 in a direction perpendicular to the paper surface.
Outer walls 43 protruding upward are also provided on both left and right sides of the lower case unit 29 over the entire length of the case unit 29 in a direction perpendicular to the paper surface. In FIG. 3, the right outer wall 41 is bent inward and is in close contact with the inner surface of the outer wall 43, and the left outer wall 43 is bent inward and is in close contact with the inner surface of the outer wall 41.

The left and right outer walls 41, 43 and the connecting portion 3
Between them, cooling air introduction spaces 45 and 47 for introducing outside air from the front of the vehicle and discharging the air to the rear are formed. Further, the cooling air introduction space 49 is also provided between the two coupling portions 31.
Are formed.

A cavity 51 penetrating in the front-rear direction of the vehicle body is formed at the upper part of the right and left ends of the upper case unit 29 in FIG. The top plate 53 is fixed by bolts 55 inserted into the bolt insertion holes 53a shown in FIG. 3, a cavity 51 penetrating in the vehicle front-rear direction is formed to protrude downward also at a lower portion of both left and right ends in FIG. 3 of the lower case body 29, and a lower wall 51b forming the cavity 51 is formed.
The bottom plate 57 has a bolt insertion hole 57a shown in FIG.
Are fixed by bolts 59 inserted into the holes.

The top plate 53 and the bottom plate 57 cover almost the entire case 25 as shown in FIG.
3 and the upper case unit 29, and between the bottom plate 57 and the lower case unit 29, the cooling air introduction space 6.
1 and 63 are formed respectively. Of these, the cooling air introduction space 63 on the lower side is formed at a portion facing the road surface.

A terminal cover 65 shown in FIG. 1 is provided above the upper case unit 29 between the left and right cavities 51 facing each other and between the two central battery housing spaces 27. Screw holes 67 for fixing to both ends of the case 25 in the front-rear direction of the vehicle body, and screw holes 69 having the same function between the two left battery housing spaces 27 in FIG. Is formed. on the other hand,
In the lower part of the lower case unit 29, screw holes for fixing the terminal cover 65 in the same manner as described above are provided between the mutually opposed portions of the left and right cavities 51 and between the two central battery housing spaces 27. A screw hole 73 having the same function is formed in the upper portion between the two battery housing spaces 27 on the right side in FIG.

The terminal covers 65 are mounted on the case 25 at both ends in the front-rear direction of the vehicle body so as to hermetically close the eight battery storage spaces 27, as shown in FIG. 6 as an enlarged perspective view of FIG. In this mounted state, the cooling air introduction holes 75 and 77 are aligned with substantially the right half of the cooling air introduction space 45 on the case 25 side, the substantially left half of the cooling air introduction space 47, and the entire cooling air introduction space 49, respectively. , 79 are formed.

The terminal cover 65 has a case 2
A bolt insertion hole 81 is provided to match the screw holes 67, 69, 71, 73 on the fifth side. This bolt insertion hole 8
1 is inserted into the screw holes 67 and 6.
9, 71 and 73, the terminal cover 65 is fixed to the case 25. At this time, the terminal cover 65 is substantially left half of the cooling air introduction space 45 and the cooling air introduction space 47.
And the cooling air introduction spaces 61 and 63 are open without being closed.

As shown in FIG. 4, the terminal cover 65 is formed with an annular fitting portion 83 which enters the battery housing space 27 in a state of being close to or in close contact with the inner peripheral surface thereof. A cylindrical collar 85 for fixing the battery cell 23 is interposed between the fitting portion 83 and the battery cell 23. A step portion 85a is formed on an inner peripheral portion of the collar 85 on the battery cell 23 side, and a corner portion of the battery cell 23 is fixed by the step portion 85a. Also, the step portion 85a
The distal end of the thin portion 85b on the outer peripheral side is in contact with the end of the insulating material 23b.

A sealing member 87 is interposed between the terminal cover 65 and the end surface of the case 25 at the outer peripheral side of the fitting portion 83. That is, the sealing material 87
The eight are integrally formed in a ring shape so as to surround the periphery of each battery accommodating space 27.

Further, on the inner surface of the terminal cover 65,
Adjacent (upper and lower in FIG. 4) battery cells 23
A bus bar 89 is provided as a terminal portion for electrically connecting each other. A male terminal 91 is provided at a position corresponding to the upper battery cell 23 in the bus bar 89 in the drawing.
However, female terminals 93 are fixed at positions corresponding to the battery cells 23 on the lower side, respectively. On the other hand, the female terminal 95 into which the male terminal 91 is fitted is fitted to the terminal 23a of the upper battery cell 23 in the figure, and the female terminal 93 is fitted to the terminal 23a of the lower battery cell 23 in the same figure. The male terminal fittings 97 to be fitted into are respectively fixed.

That is, with the terminal cover 65 attached to the case 25, the upper and lower battery cells 23 in FIG.
The two battery cells 23 provided in one case 25 are electrically connected in series with each other by such a bus bar and a terminal device. It has become. Although not shown, the battery cells 23 are drawn out from the terminals 23a of the two endmost battery cells 23 connected in series by a lead wire or the like.

An exhaust duct 99 is mounted on the rear end side of each of the two cases 25 arranged in parallel. The exhaust duct 99 is, for example, a bolt for fixing the top plate 53 and the bottom plate 57 in a state where the end of the case 25 with the top plate 53 and the bottom plate 57 attached thereto is inserted into an opening on the front side of the vehicle. By 55 and 59, it is fixed to the case 25 by fastening together with the top plate 53 and the bottom plate 57.

An exhaust fan 101 is mounted on the rear surface of the exhaust duct 99 where the opening is formed. The exhaust fan 101 is activated when the vehicle is stopped and forcibly introduces outside air into the case 25, and is stopped when the vehicle is traveling, so that traveling wind is introduced into the case 25. However, the configuration may be such that it operates when necessary.

The case 25 to which the top plate 53, the bottom plate 57, the terminal cover 65, the exhaust duct 99, and the exhaust fan 101 are mounted as shown in FIG. As shown, the vehicle body 10
5 is attached to the floor lower surface 105a. The support bracket 103 is formed by bending a plate material and is arranged to extend in the vehicle width direction. The support bracket 103 supports a lower portion of the case 25,
Fixed surfaces 109 at both ends fixed to the vehicle body floor 105a
And a connection surface 111 formed to be inclined between the support surface 107 and the fixed surface 109.

Bolts 1 for fixing the support bracket 103 to the case 25 are provided at both ends in the vehicle width direction of the support surface 107.
The fixing surface 109 is provided with a bolt insertion hole 109a for inserting a bolt 115 for fixing the support bracket 103 to the vehicle body floor lower surface 105a.

According to the battery fixing structure for an electric vehicle having the above structure, as shown in FIG.
When it is mounted on the vehicle, the outside air from the front of the vehicle
Cooling air introduction spaces 45, 47, 4 opening at both front and rear ends of 5
The cooling air passing through 9, 61, 63 and the cavity 51 cools the battery cell 23 and is discharged to the outside via the exhaust duct 99. The battery cell 23 includes an insulating material 23 on the outer peripheral portion.
Since b is in close contact with the inner peripheral surface of the battery housing space 27, the generated heat is efficiently radiated to the outside air via the insulating material 23b and the case 25, and the temperature rise of the battery cell 23 is suppressed, and the battery life is reduced. improves.

At this time, since the battery housing space 27 in which the battery cells 23 are housed is closed by the terminal covers 65 at the front and rear ends thereof, the invasion of the outside air is avoided. Space 27
Intrusion of water into the interior is also avoided. In addition, the sealing portion for waterproofing is only the mounting portion of the terminal cover 65 at the front and rear ends of the case 25 except for the portion where the lead wire is drawn out from the terminal 23a.
Can be performed as a so-called battery pack alone before the case 25 is mounted on the vehicle body 45.
Watertightness is extremely easy.

The cooling air introduction space 63 formed in the lower part of the case 25 serves to protect the battery cell 23 against pushing up by a curb or the like from the road surface when the vehicle is running, and contributes to improvement in reliability.

The case 25 is composed of two case units 2.
9 are connected to each other, the case unit 29 can be used alone. This allows the number of battery cells 23 mounted on the vehicle to be changed. Can be easily handled.

In the above embodiment, the battery housing space 27 of the case 25 has openings at both ends. However, one is closed and the terminal cover 65 is provided only at the other opening. It may be configured to be mounted. Further, the top plate 53 and the bottom plate 57 may be integrated with the case unit 29.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a battery fixing structure of an electric vehicle according to an embodiment of the present invention.

FIG. 2 is a side view of an electric vehicle including the battery fixing structure of FIG.

FIG. 3 is a front view of a case accommodating a battery cell in the battery fixing structure of FIG. 1;

FIG. 4 is a sectional view taken along line AA of FIG. 3 in a state where battery cells are housed.

FIG. 5 is an enlarged view of a connection portion between the cases shown in FIG. 3;

FIG. 6 is an enlarged perspective view of a terminal cover in the battery fixing structure of FIG. 1;

FIG. 7 is an exploded perspective view of a battery fixing structure of an electric vehicle showing a conventional example.

[Explanation of symbols]

 Reference Signs List 23 battery cell 23a terminal 25 case 27 battery accommodation space 29 case alone 31 coupling part 33 side wall 35 locking projection 37 protruding piece 39 locking projection 45, 47, 49 cooling air introduction space 65 terminal cover 89 bus bar (terminal section)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 7/20 H05K 7/20 GH

Claims (4)

[Claims] A battery storage space for housing a battery cell having terminals at both ends with its outer surface being in close contact with the inner surface is provided, and at least one end has
A terminal cover provided with a terminal portion capable of conducting to the terminal of the battery cell is provided with an opening that is hermetically mounted, and the plurality of battery housing spaces have a multi-tiered shape that is superimposed on each other, and each of the stages is mutually connected. A battery case for an electric vehicle, wherein an independent case unit is formed and the case units can be connected to each other. 2. The battery case for an electric vehicle according to claim 1, wherein a cooling air introduction space is formed between the case units. 3. A connecting portion for connecting the single case units to each other, a pair of side walls facing each other at a predetermined interval are provided on one of the case units, and a tip side of the side wall is provided in a direction facing each other. Protruding locking projections are provided, and the other case unit is provided with locking projections on both sides which are located closer to the base end side of the side wall than the locking projections and prevent the side walls from coming off from each other. 3. The battery case for an electric vehicle according to claim 1, wherein a protruding piece is provided. 4. A case unit is provided with a side wall connected to a protruding piece of the mating case unit and a protruding piece connected to a side wall of the mating case unit. 4. The battery case for an electric vehicle according to claim 3, wherein the case units have the same shape.